During times of emergency, it is important that officials be able to quickly communicate information about the emergency to large numbers of people. For example, when a tornado or other violent storm is detected, lives may be saved if citizens can be warned to take cover. Similarly, during a wildfire, it may be necessary to contact a large number of residents of the threatened area to effect a rapid evacuation.
Various warning systems exist. For example, the Emergency Alert System in the United States enables officials to interrupt commercial radio and television broadcasts to make emergency announcements. The announcements can be targeted to particular geographic areas.
The Reverse 911® system used in United States and Canada enables officials to place automated telephone calls to landline telephones in specific geographic areas. For example, authorities in a coastal area may use the Reverse 911® system to warn residents in low-lying areas of a possible tsunami after an earthquake has been detected.
AMBER Alerts or similar kinds of notifications are used in many countries to notify the general populace when a child is abducted and believed to be in danger, in hopes that a person hearing the alert will see the child and report his or her location so that authorities can act to protect the child. AMBER Alerts may be broadcast using the Emergency Alert System in the United States, but may also be distributed by many other channels.
Such prior systems may not reach persons who are not at home or who are not watching or listening to broadcast media. Recognizing the near ubiquity of cellular telephones and their ability to receive text messages, the United States federal government is now implementing the Commercial Mobile Alert System, or CMAS. CMAS is scheduled to be deployed by late 2011 in some areas, and nationwide in 2012, and will enable authorities to send text messages to all active cellular devices in targeted geographic areas. These text messages may reach people that would otherwise not be notified by other means. CMAS is intended to overlap with other systems, and will be used to broadcast many kinds of notifications, including weather and fire warnings, AMBER alerts, emergency management instructions, and other kinds of notifications.
Due to the importance of the messages broadcast by CMAS, there is a need to provide ways for additional persons to receive the messages.